1. Field of the Invention
The present invention relates to a handover method of a terminal and a system thereof in a communication system. More particularly, the present invention relates to a method and a system for changing an Access Service Network (ASN) of a Mobile Station (MS) in a communication system.
2. Description of the Related Art
In the case where an ASN of an MS in a communication system changes, the communication system needs to change a Paging Control (PC), an Anchor Data Path Function (ADPF), and an authenticator server of the MS, and re-authenticate the MS. For example, when the ASN of the MS that operates in an idle mode changes, the communication system updates the location of the MS.
After that, the communication system performs a paging for the MS and an Idle Mode-Exit (IM-Exit) procedure. At this point, the communication system switches the MS that operates in an idle mode into an active mode.
In addition, the communication system changes an ADPF and an authenticator server of the MS, and re-authenticates the MS.
After changing the PC, the ADPF, and the authenticator server of the MS, and completing re-authentication, the communication system performs a path registration release procedure in order to switch the mode of the MS to the idle mode.
As described above, when the ASN of the MS changes, a delay occurs while the MS and the ASN transmit/receive messages for changing the PC, the ADPF, and the authenticator server. In this case, the MS may fail to enter a network due to the delay caused by message transmission/reception.